The present invention relates to providing power and, more specifically, to providing a compact, high-voltage power converter module.
Power converters are used to convert power from an input to a needed power for provision to a load. One type of power converter is a transformer. Power converters may be designed to convert a fixed AC or DC input voltage into a higher or lower AC or DC voltage. The architecture chosen may provide for high frequency operation, pulse-width-modulation, isolation, and the like.
An example of a power converter is a transformer. Different types of transformers may be used depending on a particular application. A typical power transformer includes one or more input windings and one or more output windings. The input and output windings are both wrapped around a core formed of a magnetic material. An alternating current provided at the input (e.g., primary) windings causes a varying magnetic flux in the transformer core. This flux leads to a time varying magnetic field that includes a voltage in the output (e.g., secondary) windings of the transformer.
In some cases, the core is so-called “closed-core.” An example of closed-core is a “shell form” core. In a shell form, the primary and secondary windings are both wrapped around a central core arm and are both surrounded by outer arms. In some cases, more than one primary winding is provided and multiple secondary windings may also be provided. In such systems, based on the input and to which of the primary windings that input is provided (of course, power could also be provided to more than one primary winding in some instances) different output voltages can be created at each of the secondary windings.
Power converters for Power Branching Unit (PBU) for undersea applications need to reconcile conflicting requirements of high power density and exceedingly high reliability (e.g., 20 years of un-serviced operation). Consider FIG. 1. In particular, in FIG. 1, a low voltage region 102 is shown separated from a high voltage region 104 of a PBU 100 by an insulation barrier 106. Each region 104, 106 includes one or more components such as a winding or a power inverter that are generally shown by elements 108, 110, respectively. Coronal discharges (shown by arrows 112, 114) and eventual insulation breakdown may be caused by voltage concentration across the air gaps 116, 118 between component's edges and the insulation barrier 106. Insulation includes air (gap between the barrier and the edge of component) and solid material (inside the barrier). When voltage is applied across two dissimilar materials such as air and solid dielectric, the material with the lower permittivity (air) will receive higher stress. This problem is further complicated by the fact that voltage breakdown of air is sensitive to changes in humidity and altitude.